Viral persistence in the presence of cART continues to be the barrier to a potential functional or eradication cure of HIV infection. This is hypothesized to be due to the presence of a long-lived reservoir of blood and tissue CD4+ T cells with latent HIV infection. The small percentage of HIV-infected individuals who control HIV disease progression for many years without cART, collectively termed NP (i.e., nonprogressors), offer a natural model of viral control and clues to curing the infection as well as developing therapeutic and prophylactic vaccines. For over 20 years it has been known that professional antigen presenting cells (APC) can mediate explosive HIV replication in CD4+ T cells, termed trans infection. However, the importance of this in vitro phenomenon in HIV infection and disease progression has been uncertain. We have recently reported that APC from NP lack the ability to trans infect CD4+ T cells. This phenotype was related to a unique, enhanced metabolism of cholesterol in the APC of these NP and it appears to be a genetic trait. Our central hypothesis is that professional APC from NP have a remarkable inability to trans infect autologous and heterologous CD4+ T cell targets which underlies their long term control of HIV infection, and this is linked to altered cholesterol metabolism within their APC. We propose an in depth analysis of the biologic and genetic basis of the altered cholesterol metabolism that prevents HIV trans infection in NP as described in the following specific aims: Specific Aim 1. Confirm and extend our understanding of the biologic basis for the lack of HIV trans infection in a broad, well-defined spectrum of NP. Specific Aim 2. Define the genetic and epigenetic factor(s) responsible for the lack of trans infection in these individuals. Specific Aim 3. Analyze HIV trans infection and APC-T cell pathways in myeloid and lymphoid APC of NP that underlie their lack of trans infection. We believe that greater knowledge of this phenomenon through the proposed R01 grant will have a significant, transformative effect on how to control HIV disease progression and in developing a functional cure for HIV infection.